1. Field of the Invention
The present invention relates to a connecting mechanism for connecting a test head which tests an integrated circuit (hereinafter, it may be simply referred to xe2x80x9cICxe2x80x9d) to an automatic handler sorting the IC according to a result of the test by the test head, particularly, to a connecting mechanism for connecting a test head to an automatic handler having a low temperature testing function.
2. Description of Related Art
As an automatic handler which is connected to an IC tester, the one that cools IC under test and tests electric characteristics of the IC under test in a low temperature environment has been known. In other words, an automatic handler having a low temperature testing function has been known. Hereinafter, such automatic handler may be simply referred to xe2x80x9clow temperature handlerxe2x80x9d. The low temperature handler has a dry air supply unit which supplies dry air to a testing portion (for example, a testing box in a thermostat) in order to prevent a frost formation in the testing portion when the low temperature handler tests the IC under test in the low temperature environment.
FIGS. 3, 4A and 4B show an example of an IC test system including the low temperature handler, according to an earlier technology. FIG. 4A shows that the low temperature handler and a test head are separated from each other. FIG. 4B shows that the low temperature handler is connected to the test head.
The IC test system 1 has, as shown in FIGS. 3, 4A and 4B, the test head 2 and the low temperature handler 3. The test head 2 is provided with a testing box 21 on which a contact board 24 is disposed. The contact board 24 has IC sockets 23. Coupling cables 28 are connected to the contact board 24 through connectors 25, and also connected to a test head body 20 through a base board 29 with being surrounded closely by packing 29a for a cable outlet or exit, as shown in a central ruptured portion of FIG. 3. The testing box 21 is provided with an air intake 26 for frost formation prevention for letting dry air from a dry air supply unit in the testing box 21 through a piping hose 27. The low temperature handler 3 has a thermostat 31, a transfer carrier 32, a contact pusher 33 and a piping hose 35 (see FIGS. 4A and 4B) which is connected to the dry air supply unit (not shown).
When ICs are tested with the IC test system 1, the test head 2 is moved to the low temperature handler 3. Then the testing box 21 is inserted in the thermostat 31, inside of which is kept the low temperature environment, thereby the test head 2 is connected to the low temperature handler 3, as shown in FIG. 4B. Leads of the ICs under test transferred by the transfer carrier 32 are pressed against contacts of the IC sockets 23 by the contact pusher 33 to be brought into contact with the contacts. Thus, electric characteristics of the ICs in the low temperature environment are tested. At this time, the piping hose 27 and the piping hose 35 are connected to each other through junction connectors 37 at outside of the low temperature handler 3 and the test head 2. The dry air is supplied to the testing box 21 from the dry air supply unit through the connected piping hoses 27 and 35, suppressing entering of moisture of outside air from spaces between the coupling cables 28 and the packing 29a to the testing box 21 during the IC test. Thereby, the frost formation in the testing box 21 is prevented.
With the IC test system 1, aside from a connection between the test head 2 and the low temperature handler 3, the piping hose 27 of the testing box 21 is connected to the piping hose 35 of the low temperature handler 3 through the junction connectors 37. Thus, when the test head 2 and the low temperature handler 3 are connected to or separated from each other, in addition to the connection or separation of them, the connection or separation of the piping hoses 27 and 35 is required, taking a lot of time. Furthermore, a person may forget the connection between the piping hoses 27 and 35 when the test head 2 and the low temperature handler 3 are connected to each other.
When the test head 2 is separated from the low temperature handler 3, if the piping hoses 27 and 35 are left connected, the piping hose 27 of the test head 2 pulls the piping hose 35 of the low temperature handler 3. Thus, the piping hoses 27 and 35 may become wrong or be damaged. Furthermore, during the transfer of the test head 2, a person should pay attention to the piping hose 27 which is connected to the testing box 21. Thus, the operations for them are complicated.
The present invention was developed in view of the above-described problems. Therefore, an object of the present invention is to provide a mechanism for connecting a test head to an automatic handler, that makes an IC test system capable of testing an IC under test in a suitable temperature environment not by complicated operations but merely by connecting the test head to the automatic handler.
In order to accomplish the above-described object, in one aspect of the present invention, a mechanism for connecting a test head to an automatic handler comprises a piping for connecting the test head to the automatic handler, and a fluid supply means for supplying fluid in the test head through the piping and for keeping a testing environment for an IC under test. The fluid may be for preventing a frost formation. The piping comprises a first piping portion which is provided to the automatic handler and which has a first piping connection opening. The piping also comprises a second piping portion which is provided to the test head and connected to the first piping portion. The second piping portion has a second piping connection opening which is connected to the first piping connection opening when test head is connected to the automatic handler.
The fluid may comprise whatever that is supplied to the test head for keeping the testing environment the desired one and prevents the frost formation when the IC under test is tested. For example, dry air may be used for preventing outside air from entering the test head and preventing the frost formation to be generated.
According to the mechanism, the piping connection openings are connected to each other at the same time that the test head and the automatic handler are connected to each other, so that the first piping portion and the second piping portion are connected to each other.
Thus, the fluid which prevents the frost formation, for example, compressed fluid, is supplied to the test head from the fluid supply means, merely by connecting the test head to the automatic handler, so that the electric characteristics of the IC under test can be tested by the test head with the predetermined testing environment kept.
That is, except the connection between the test head and the automatic handler, the operations of connection between the test head and the fluid supply means for supplying the fluid to the test head, such as the connection of piping hoses, are not required. Accordingly, forgetting of the connection between the piping of the fluid supply means of the automatic handler and the piping of the test head, or the interference by each piping hoses when the automatic handler and the test head are separated from each other, as in the earlier technology, is solved. Particularly, during the separation of the test head from the automatic handler or the transfer of the test head for connecting it to the automatic handler, the interference by the piping hoses is reduced. Thus, the automatic handler and the test head can be smoothly connected to each other. Furthermore, when the test head is separated from the automatic handler, the piping may not become wrong or be damaged by forgetting the operations for the separation of the piping for supplying fluid to the test head, differing from the earlier technology.
The automatic handler may comprise a thermostat. The test head may comprise a testing box which is inserted in the thermostat. The testing box may be provided with an IC socket which is brought into electrical contact with the IC under test. When the testing box is inserted in the thermostat, the first piping connection opening of the automatic handler and the second piping connection opening of the test head may be connected to each other in a contacting portion between the thermostat and the testing box.
According to the mechanism, the first piping connection opening of the automatic handler and the second piping connection opening of the test head may be connected to each other in the contacting portion. Thus, when the testing box having the IC socket is inserted in the thermostat, the fluid supply means and the test head may be connected to each other through the first and second piping portions. Therefore, the advantage described above may be obtained.
The fluid which is supplied to the test head from the fluid supply means may comprise dry air.
According to the mechanism, when the electric characteristics of the IC under test are tested by the test head, merely by connecting the test head to the automatic handler, the dry air from the fluid supply means may be supplied to the test head, preventing the outside air from entering the test head to prevent the frost formation. Thus, the electric characteristics of the IC under test may be tested in the suitable low temperature environment.
The automatic handler may be a horizontally conveyer type and have a function for keeping a low temperature, and the frost formation in the test head connected to the automatic handler may be prevented.
According to the mechanism, the frost formation in the test head may be prevented merely by connecting the test head to the automatic handler, which may be the horizontally conveyer type having the low temperature keep function.